Mineral aerosol production by wind erosion: aerosol particle sizes and binding energies

Size distributions of mineral aerosols released by wind-erosion from arid areas are of primary importance to model their transport patterns as well as their effect on climate. Wind tunnel experiments meant to test the influence of wind strength and soil characteristics are carried out with two natural soils differing both in texture and in mineral composition. In all cases, the aerosols can be considered as mixtures, in proportions depending on wind speed, of the same three lognormally distributed particle populations. By using appropriate binding energies for these populations, a sandblasting model previously developed allows retrieval of the size distributions of the aerosols produced by the two soils at any wind speed. A major implication of this study is that the site distributions of mineral aerosols greatly depend on the wind conditions prevailing during their generation. Aerosols optical properties being size dependent, this should clearly be taken into account in climate modeling.